I am looking to change mass, center of mass and inertia tensor on PartOperations and MeshParts to be more accurate than they currently are. As you may have noticed, those three values are currently calculated using the bounding box of the object. This is not correct.
What I am here to ask is, how will this affect you? Are you currently reliant on these values physically simulating as they are now? Possible scenarios where this might be the case could include the use of body movers or constraints with CSG/MeshParts. Keep in mind, this change will have no impact on the physical geometry itself.
Please provide specific examples if you have them (pm me models/places if needed). I would really like to get an idea of the potential repercussions of this change by seeing how you use CSG/PartMeshes.
Will this be affected by CollisionFidelity? i.e. a part with Box CollisionFidelity will still calculate these values from the bounding box, while a part with a Default (highest-quality) CollisionFidelity will have the values closer to what you’d expect for its appearance.
If not, I suggest that be the case. CoM, mass, etc should be based on how the objects physically interact with the world, which is different based on these objects’ CollisionFidelity.
While your messing with meshparts can you please please please let us resize them like we do unions? I don’t like having to convert all my stuff to SpecialMesh FileMeshes and hoping that the texture update works on SpecialMeshes when it does come out.
Mass and center of mass should be the same for box collision fidelity. Inertia tensor will be slightly different as we were previously calculating it as a hollow box
If we’re already changing center of mass, why not make it a property so we can adjust it ourselves? Some of my aircraft for example are very carefully balanced with the center of mass in the middle of the collision box - if the center of mass just changes, I’d have to re-do a lot of that work…
I’m perfectly fine with the default behavior changing as long as there’s a way for me to revert those changes where I need to.
I also might have issues with my boats having their CoMs moved – If I’m able to adjust it like an attachment though, there shouldn’t be any issue.